Brake Fluid Flush: DOT3, DOT4, DOT5?

[backeis]

About to replace all hydraulic cylinders (clutch and brake), stainless steel brake lines, clutch line, and wheel cylinders, and thereby will also do a brake fluid flush, to finally nip my brake fluid leak in the bud.

When it comes to flushing and replacing the fluid, what DOT number and brand is best recommended? I read all kinds of recommendations across the forum. I'm not racing the car, so getting near any boiling points shouldn't be an issue. Brakes front and rear were rebuilt 2016, no upgrades.

 

What fluid should I shop for?

[02Pilot]

DOT 4. Flush every couple of years and you likely won't be doing other brake work again for some time.

[Buckeye]

29 minutes ago, backeis said:

What fluid should I shop for?

 

https://www.fcpeuro.com/products/amber-brake-fluid-dot4-dotamber

[Healey3000]

DOT 5 is silicone-based and should not be used in a system that has DOT 3 or 4.  Brakes may break if you do.

[irdave]

Is DOT 3 not the suggested fluid?  I always thought front discs / rear drums would run on DOT 3 no problem.

 

And to say it again out loud,

 

1 hour ago, Healey3000 said:

DOT 5 is silicone-based and should not be used in a system that has DOT 3 or 4.  Brakes may break if you do.

 

And that DOT 5.1 is different fluid still, and if memory serves, should be compatible with DOT 4 systems.

[Healey3000]

3 minutes ago, irdave said:

And that DOT 5.1 is different fluid still, and if memory serves, should be compatible with DOT 4 systems.

I believe you are correct.

 

My favorite is Castrol LMA (low moisture absorption) brake fluid.  Never had any issues with my braking systems with that product.  DOT 3, I think...

[irdave]

5 minutes ago, Healey3000 said:

I believe you are correct.

 

My favorite is Castrol LMA (low moisture absorption) brake fluid.  Never had any issues with my braking systems with that product.  DOT 3, I think...

 

I've also had good luck with the ATE type 200 and super blue, being able to alternate back and forth.  But it appears Super Blue is NLA.  Thanks DOT.  And it's usually not easy to get in a pinch.  And I never really beat on it hard.

 

What is usually pretty easy to get is Motul RBF600- usually at most motorcycle shops, especially the Kawasaki shops seems- and it's really good fluid.

 

Both of these are way overkill for a 'normally' driven, gently driven 2002, but are very good fluids.

[Stevenc22]

I always use Valvoline Dot3/4 synthetic. It has a really high boiling point and avaliable at any autozone

 

[02Pilot]

For normal street use the particular brand of fluid, and even the boiling points, are far less important than changing it frequently.

[M3M3]

what andrej said.  for normal street use  any dot 3 or 4 fluid you find in the local auto parts store will be perfect.  don't bother spending big bucks on motul or ate.   castrol lma, valvoline, prestone....all will work fine.  the key is to bleed the system annually.

 

(note - this is NOT the advice i would give to anyone tracking a car or driving hard on mountain roads)

 

you don't want your brakes to look like this!

 

 

[Conserv]

8 hours ago, irdave said:

Is DOT 3 not the suggested fluid?  I always thought front discs / rear drums would run on DOT 3 no problem.

 

 

Yes, BMW specified DOT 3, emphasizing it with a blue underhood sticker on square taillight cars: “....USE ONLY DOT 3 FLUID FROM A SEALED CONTAINER”. ?

 

Regards,

 

Steve

Edited April 17, 2019 by Conserv

[Mark92131]

4 hours ago, Conserv said:

blue underhood sticker

 

Steve:

 

Where did you get that sticker?  I like your Emission Sticker ;-).  You need to find some caps for those 2 brake fluid reservoir screws before you impale yourself.

 

Mark92131

[Conserv]

21 minutes ago, Mark92131 said:

 

Steve:

 

Where did you get that sticker?  I like your Emission Sticker ;-).  You need to find some caps for those 2 brake fluid reservoir screws before you impale yourself.

 

Mark92131

 

Thanks, Mark,

 

On the first item: I don’t know! Most of the “sticker kits” come with it — Lajolla Independent, eBay, BMW 2002 Car Club of Columbia — but the quality varies. My ‘76’s underhood stickers are now (1.) a melange of stickers culled from several “sticker kits” acquired since 1983 from multiple sources, all of which are forgotten and, although probably documented in my receipts, likely came from vendors no longer in business, e.g., Bimmer Parts; (2.) gifts from colleagues ?; and (3.) a few one-off stickers done by Car-Bone out of Poland.

 

All the sticker kits got combined and then I picked those closest to the originals.

 

On your second item, thank you very much! Few ‘02 owners are familiar with the various versions of the emissions schematic....?

 

On your final item, Steve Tochi already sent me a period screw cap, apparently sharing your concern over the sharp edges. I thought I had one surviving original cap, but I guess it got lost during the Big Re-Paint. So we’re working on it!

 

Below are two examples of the original brake fluid sticker: the first is my ‘76 in August 1983; the second is a Sienabraun ‘76 Jim Gerock came across for sale in Virginia(?).

 

Thanks and best regards,

 

Steve

 

 

Edited April 17, 2019 by Conserv

[02Les]

And, here's one more from an Apr '76 car.

[thinksound_mike]

7 hours ago, Stevenc22 said:

I always use Valvoline Dot3/4 synthetic. It has a really high boiling point and avaliable at any autozone

 

That's what I use. Does the job, easy to find and cheap!